The invention relates to a mechanism for uniting valve parts composed of a male half and a female half, the female half comprising an inner valve stem attached to a supporting ring and a slider acted on by a spring.
It is known that in order to prevent the ingress of air or the loss of fluid when the connectors of hydraulic systems are being connected and disconnected, special connectors whose mutually opposing surfaces are without projections are used. These connectors are described as flat-faced quick-release couplings.
At present these connectors consist of two parts: a male half and a female half.
The male half has a tubular outer body with standard geometry and dimensions and a cylindrical valve body whose flat end surface closes the opening of the outer body.
The female half has a valve stem fixed by means of a valve guide to a supporting ring in order to define channels through which a fluid may flow. The supporting ring in turn is fixed to a fixed outer body.
An inner slider and an outer slider, both springloaded, are housed in the outer body, in which they can slide. The sliders open and close the fluid flow channels.
The coupling end of the outer body comprises a device for locking and releasing the male half.
The male half is coupled to the female half by pushing the ends of the outer body and valve body of the male half against the sliders and valve stem of the female half. The outer body of the male half slides into the outer body of the female half until it is locked by the locking device. The valve body of the male half, being applied against the valve stem of the female half, retreats and opens the fluid flow channels. The locking of the body of the male half by the locking device of the female half occurs simultaneously with the opening of the valves (the sliders of the female half and the valve body of the male half).
These flat-faced quick-release couplings are used as connectors in hydraulic circuits, such as the hydraulic circuits of agricultural machinery and earth levelling machines. They are used especially for connecting the hydraulic circuit of a tool to the power unit.
It frequently happens that the hydraulic circuit is disconnected by opening the connection when there is still pressurized fluid inside. Often, too, the pressure in the disconnected hydraulic circuit rises because of heating of the fluid.
In these situations there is pressurized fluid inside the disconnected male part. The male half is usually attached to the end of the hydraulic circuit of a tool that has no means of regulating the pressure.
The pressurized fluid present inside the male half exerts a force tending to oppose the opening movement of the valve body, rendering connection of the male half to the female half extremely difficult if not impossible.
It also often happens that where an operator of, say, an agricultural machine has to operate in the vicinity of the tool connected up to the latter, he will first pressurize the hydraulic circuit leading to the female half before proceeding to connect up the hydraulic circuit of the tool.
The pressure of the fluid inside the female half makes it a very difficult task to connect up the male half since the pressure of the fluid opposes the movement of the internal slider to open the fluid flow channels.